1. Field Of The Invention
The present invention relates generally to a drill stem test string including tubing conveyed perforating guns, and more particularly, but not by way of limitation, to an adapter for a compression set packer which allows the combination of a drill stem test string with a tubing conveyed perforating string.
2. Description Of The Prior Art
During the completion of a well it is desirable to flow test the well after the well is perforated. It is particularly desirable to be able to flow test the well in an unbalanced condition wherein the pressure in the well is substantially lower than the formation pressure when the subsurface formation is initially perforated.
One system which accomplishes this general purpose is that shown in U.S. Pat. No. 4,915,171 to McMahan, and assigned to the assignee of the present invention. The McMahan patent discloses an above packer perforate test and sample tool which allows well annulus pressure above the packer to cross over into the tubing string to actuate a pressure actuated firing mechanism for the tubing conveyed perforating guns.
U.S. Pat. No. 4,804,044 to Wesson et al., and assigned to the assignee of the present invention, discloses another system which operates in a manner somewhat similar to the McMahan '171 patent.
The prior art also includes a compression set packer actuated by setting down weight on the packer. One example of such a tool is that sold by Halliburton Services, the assignee of the present invention, under the trademark Champ.RTM. III Packer. The details of construction of the Champ.RTM. III Packer